Dumbbell Skull Crusher
A triceps isolation exercise performed lying on a bench, lowering dumbbells toward the forehead to build size and strength in the back of the arms.
How to do it
- 1Lie on a bench holding a dumbbell in each hand, arms extended straight above your chest.
- 2Keeping your upper arms still, bend your elbows to lower the dumbbells toward the sides of your head.
- 3Stop just before the dumbbells reach your forehead.
- 4Extend your elbows to press the dumbbells back to the starting position.
Common mistakes
- Letting the elbows flare outward or drift back over the face instead of staying fixed in place.
- Using a weight heavy enough that the shoulders have to help drive the movement.
Sets & reps by goal
| Goal | Sets | Reps | Rest |
|---|---|---|---|
| Strength | 2-3 | 8-12 | 60-90 sec |
| Build muscle | 2-3 | 10-15 | 45-60 sec |
| General fitness | 2-3 | 12-15 | 45-60 sec |
Ranges reflect the same goal-based logic used by the workout plan tool. Actual set count in a generated plan also depends on how often this muscle group appears elsewhere in your week.
Frequently asked questions
Is the Dumbbell Skull Crusher safe for beginners?
Yes. The Dumbbell Skull Crusher is tagged as beginner-friendly in GetFitArchitect's exercise database, meaning it doesn't demand much prior strength or mobility. Start with a weight or resistance level where you can complete every rep with good form, and only add load once that feels controlled.
What muscles does the Dumbbell Skull Crusher work?
The primary mover is your triceps. As a push movement, it also involves your chest and shoulders.
What can I substitute if I don't have dumbbells or bench for the Dumbbell Skull Crusher?
The Diamond Push-Up targets the same primary muscle with different equipment, so it's a reasonable swap if you don't have dumbbells or bench available.
See the Diamond Push-UpRelated exercises
Learn more
Want a full plan built around exercises like this one? Try the workout plan tool.